Friday, February 05, 2010

The Scientist | Biologists have traditionally left quantum theory to physicists. But the complicated interactions between matter and energy predicted by quantum mechanics appears to play a role in photosynthesis, according to a study published this week in Nature -- affecting how energy from the sun makes its way to a cell's reaction centers before being converted to chemical energy that powers cellular functions.

"The main surprise was that you could actually see" these quantum effects influencing real world biology, said biophysicist Rienk van Grondelle of VU University in Amsterdam, who did not participate in the work, and "that you could observe this phenomenon underlying how [photosynthesis] was working."

Quantum mechanics is a theory that describes the behavior of subatomic particles such as photons and electrons. But scientists have long believed that predictions made by the theory would only be evident in an idealized world that lacks environmental noise of molecules moving around and bumping into one another. People thought that "at room temperature, the noisy environment would kill this kind of quantum interaction," said van Grondelle, who wrote an accompanying review in Nature.

But examining the light-harvesting systems of two species of photosynthetic algae, physical chemist Gregory Scholes of the University of Toronto and his colleagues observed that energy introduced to the system acted in a distinctly quantum manner, even at ambient temperatures.